#include <stdio.h>
#include <string.h>
#include <algorithm>
using namespace std;

unsigned int shu[250005];
int n;
double ans;
int main()
{
	int i;
	while (scanf("%d", &n)!=EOF)
	{
		for (i=1; i<=n; ++i)
			scanf("%d", shu+i);
		sort(shu+1, shu+n+1);
		if (n%2 == 1) printf("%.1lf\n", shu[n/2+1]*1.0);
		else 
		{
			ans = (shu[n/2]+shu[n/2+1]*1.0)/2;
			printf("%.1lf\n", ans);
		}

	}

	return 0;

}
